Since this is from 2018 I’m sure it won’t do good haha but I also have a 2013 VW Jetta SE 2.5L. When I use super gas it seems to be shifting great. When I get low on gas or when I use regular gas it shifts funky. It’s weird but what I think it needs maybe is a factory reset of the computer. Idk.. I changed the valve cover thinking it could’ve been the PCV valve but that didn’t fix the issue. I also have the issue where it has trouble starting after I fuel up. Could be fuel filter or fuel pump which I’m going to replace soon to see what that does.